Existing display devices, such as televisions, can match network protocols when the display devices are connected to HDMI dongles through HDMIs. Then, when the display device is controlled by an external device such as a remote controller, a keyboard, or a mouse, the display device can be used to browse web pages or watch online videos. Thereby, the common television is updated to an intelligent television. However, the HDMI dongle and the television have not been integrated by manufactures, and must have their own systems which are independent of each other and their own power supplies. Thus, when the HDMI dongle does not completely match the display device, the HDMI dongle must have its own power cables and adapter. The number and complexity of the cables between the HDMI dongle and the display device is thus increased, and the working stability of the HDMI dongle and the display device is poor.